LOTT August 2000 Wastewater Resource Management Plan Budd Inlet Scientific Study: An Overview of Findings The LOTT Partners – Lacey, Olympia, Tumwater, and Thurston County – have invested over $3 million in an 18-month long scientific study of Budd Inlet. The results helped show to what extent Budd Inlet could be relied upon for continued and/or expanded discharge of the community’s treated wastewater flows in the future. If environmentally acceptable, additional winter discharge could offer a comparatively low cost way to gain reserve capacity as LOTT moves toward new wastewater recycling options. The scientific study final report was published in August 1998, and findings are also summarized in LOTT’s Wastewater Resource Management Plan. Summary of Study Findings The Budd Inlet Scientific Study is designed to answer several questions What’s Inside? which are key to LOTT’s Wastewater Resource Management Plan. The following presents a capsule summary of some answers offered by the Budd Inlet’s “Bathtub Theory” is Down the Drain ....... page 2 study: • Initial modeling results confirm that increased winter LOTT discharge Beachcombers Contribute to Budd Inlet Study .......... page 2 won’t harm Budd Inlet. Dissolved oxygen levels and other key water Study Pinpoints Bacteria Sources ............................... page 3 quality factors will remain largely unchanged. • Circulation in Budd Inlet is much stronger than previously under- Dissolved Oxygen Impacted by Plankton Growth ...... page 3 stood. Follow the Nutrients ................................................. page 3 • Circulation is good in both winter and Sediments Don’t Muddy the Waters .......................... page 3 summer months – it takes just 8 to 12 Scientific Information Collected days to replace the for Budd Inlet Study .................................................. page 4 entire water volume in Budd Changes Needed to Discharge More Inlet. in Budd Inlet .........................................................pages 4-5 • The low return of Budd Inlet – Comparing Wet vs. Dry Months .........pages 4-5 drift cards from Eld and Totten Inlets Computer Model Helps Answer indicates LOTT discharges have little impact on shellfish harvest. “What If” Questions .................................................. page 5 • Most of the fecal coliform bacteria in Budd Inlet – 93% – comes from What’s the Capitol Lake Connection? ......................... page 5 two sources: Capitol Lake/Deschutes River and Moxlie Creek. LOTT’s treatment plant adds less than 1%. An Introduction to the Budd Inlet Science Team ........ page 6 • Low dissolved oxygen (DO) levels in Budd Inlet occur in summer and Cost of the Study ...................................................... page 6 early fall months only, are lowest near Capitol Lake and in East Bay, and are linked to plankton growth cycles and weaker tides. Agency Involvement in Budd Inlet Study ................... page 7 • Water quality is much better in winter months, with DO levels well Peer Review Gives Independent Look above State standards. at Study Approach .................................................... page 7 • LOTT is a very small contributor to winter nutrient levels in the Inlet. Another local source of nutrients – Capitol Lake/Deschutes River – is Does Budd Inlet Study Conform more prominent. Puget Sound is the dominant source. to Public Values? ....................................................... page 8 • LOTT’s earlier investment in nitrogen removal technology is paying Where is the Study Available?.................................... page 8 off. Nutrient levels in Budd Inlet are reduced from historical levels. • Organic material reaching the sediment decays rapidly; released For More Information ................................................ page 8 nutrients are not stored long enough to carry over into sensitive summer months. 1 Budd Inlet’s “Bathtub Theory” is Down the Drain Beachcombers Contribute to Budd Inlet Study Scientists using the latest sonar technology were able to compile the One unique approach used for the Budd Inlet Scientific Study first clear picture of marine circulation in Budd Inlet. The circulation involved South Puget Sound area beachcombers and other citizens in patterns divide Budd Inlet roughly in half. Along the western shore, the actual collection of important data. water flows into the Inlet from Puget Sound. Here, the water is colder, faster moving, more saline (saltier) and cleaner. Circulation The gauges that oceanographers use to measure marine currents must patterns along the eastern shore carry water out of the Inlet. There is be anchored at depths greater than 30 feet, to avoid ships’ keels and also a gyre in the central Inlet where the marine waters swirl (see propellers. That leaves a “blind spot” in the currents that flow closer diagram). to the surface which can’t be captured by the scientists’ meters. Scientists had assumed that summertime conditions in the Inlet One method used to find the direction of these resemble a bathtub, with little movement of water. The facts show surface currents is to drop “drift cards” into the that the flushing rate for Budd Inlet is much faster than most other water at fixed locations and intervals. These inlets in Puget Sound. It takes just 8 to 12 days to replace the small wooden cards float on the water surface, entire water volume in then are later collected and reported or returned Budd Inlet. Circula- by beachcombers, boaters and others. The drift Budd Inlet Summer Circulation* – cards are brightly colored to make them easy to spot, It's No Bathtub tion is about 30% stronger in the rainy and coded to reveal the time and location of their Squaxin months, when release. A telephone number lets beachcombers report Island more freshwater their findings by phone. Boston flows into the Harbor This data collecting technique has proven highly effective Eld Inlet 239 Lighthouse Inlet. But since the 275 for the Budd Inlet Study. Of the 9,000 cards dropped into main water source that Budd Inlet, over 4,600 have been reported/returned. Cards flushes Budd Inlet has been were found as far away as Alaska. This return rate – 51% – is the 84% 16% found to be tidal pumping, highest in history for any Puget Sound study (see diagram below for 52 circulation is good during survey results). 294 both winter and summer The final tally shows that only 2% of the drift cards were returned from 327 months (see box). 52% Eld and Totten Inlets. This finding suggests there would be little impact 153 on shellfish harvest if LOTT increased its discharges into Budd Inlet. 48% 174 Priest 143 Point Thanks, beachcombers, for contributing to the study! 14 0.5 LOTT Treatment Plant 6 Drift Card Distribution – Final Tally Capitol Lake October 1996 – December 1997 Hwy. 101 I-5 D e s c h u t e s R 18% i v e I-5 r * Circulation is measured in cubic meters per second Case Inlet 8% Flushing Rates – Harstine Puget Sound Water Bodies Island McNeil 25% Island Water Body Flushing Time (days) Devil's Head Zone 2% Anderson Drayton Pass Island Port Ludlow 1 Totten Inlet Dana Passage Zone Budd Inlet 8-12 Nisqually Main Basin 20 Reach Zone Zone Budd Inlet Entire Puget Sound* 90 Eld Inlet 47% 47% – Budd Inlet - Dana Passage Southern Puget Sound 120 25% – Case Inlet to Nisqually Reach 18% – North of the Tacoma Narrows Dabob Bay ~700 8% – Between Nisqually Reach and the Tacoma Narrows 2% – Eld, Totten, and Hammersley Inlets and Pickering Passage * Includes: Admiralty Inlet, Hood Canal, Deception Pass, Tacoma Narrows, Nisqually Reach, and Dana Passage The low return of drift cards from Eld and Totten Inlets indicates LOTT discharges have little impact on shellfish harvest. 2 Study Pinpoints Bacteria Sources Dissolved Oxygen Impacted by Plankton Growth The study explored possible sources of bacterial contamination in There have been concerns for many years about water quality in Budd Budd Inlet. The presence of fecal coliform was monitored to find the Inlet. In summer months, the Inlet has low dissolved oxygen (DO), extent and origins of human-caused bacteria. Samples were taken at which harms fish habitat. This condition is caused by algae growth and every freshwater source, and also at the outfalls for LOTT and other decay, and other factors. sewage treatment plants. The recent study results confirm the existence of low DO conditions This year-round investigation revealed that nearly all of the fecal in summer months, with the lowest levels found next to Capitol Lake. coliform bacteria in Budd Inlet – 93% – comes from just two sources. The strong relationship between low DO levels and plankton growth Capitol Lake/Deschutes River contributes 50% of the bacteria; and cycles is also confirmed by the Budd Inlet Study. Plankton growth is Moxlie Creek adds 43%. LOTT’s treatment plant contributes less than 1%. much faster in months having more sunlight, with intense blooms in spring and summer months. The lowest DO levels in Budd Inlet occur as these growth cycles end, when decaying plankton consumes Follow the Nutrients the dissolved oxygen. Winter conditions in Budd Inlet are much better than in summer One major goal of the Budd Inlet Scientific Study was to carefully months. Dissolved oxygen levels in winter are good – 7 to 8 track all of the various sources of nitrogen that enter Budd Inlet – milligrams (mg) per liter (L) – well above the State standard of 5 mg/L. including discharges from LOTT’s plant. Circulation in the Inlet speeds up with increased rainfall, and algae In summer months, nitrogen can act like fertilizer, speeding up algae growth is limited in winter by the lack of sunlight. growth in marine waters. As algae blooms die at the end of The Study Shows that LOTT is a this growth cycle, the levels of Small Contributor to Winter Nutrient Sediments Don’t Muddy the Waters dissolved oxygen in Budd Inlet (Nitrogen*) Levels in Budd Inlet can plummet, harming fish WHOLE INLET Some nutrients are trapped in sediments for a time, and habitat. can return later to the water column. Sources of the Puget Sound ❆ Marine Water Sediments nutrients – called particulate organic nitrogen (PON) – Studies now confirm that LOTT is 78-83% 2-11% LOTT include dying algae and plankton fecal matter.